Test pipe or 3" Cat

[kermit]

How much performance would I loose with a 3" cat over a 3" test pipe on a 3" exhaust. I'm planning on using a t3/t4 turbo and hoping to run 300-350hp.

[goforthz28]

Between nil and Jack crap. If u pick up a high flow cat, u can see right through the thing. and especially with a 3" exhaust, it wont effect performance at all. There is trivial pressure drop through an entire, complete 2.5" exhaust so u definitely hav nothin to worry about. Its only about are you willin to spend the money. I thoroughly enjoy whoopin ass and then informing of my complete emission system including functional charcoal canister.

My two cents. Good luck

~Mark

[The Popes Bro]

what I don't like about 3" cats is that they use the same core as a 2.5" cat....

[jbodytech]

Also it depends if there are emissions laws in your area. For example out in my neck of the woods, we have emission tests every two years required for vehicle registration

[kermit]

In Michigan, emissions are not a concern, but there is still no reason to not run a cat if it doesn't give any performance benifits. Also it gets rid of the bad exhaust smell that seems to come with running without a cat.

[camarobutcher]

Here in Wisconsin, we have to do emissions every two years. If your car is 20 years or older, you can register it as a collector car and don't have to do emissions or get new tags every year.

[Kevin]

Quote:

Originally Posted by camarobutcher Here in Wisconsin, we have to do emissions every two years. If your car is 20 years or older, you can register it as a collector car and don't have to do emissions or get new tags every year.

Only in a few counties... Dane is not one of them.